Ried

I would suggest these free programs as well:

McAfee Site Advisor--free version. The folks there check out websites and based on their findings, rate it as Safe, Unknown, Caution, or Bad.

SpywareBlaster 3.5.1 to help prevent spyware from installing in the first place. Install & update SpywareBlaster with the latest definitions. After you have updated, click the button - enable protection for all unprotected items.

Spyware Guard to catch and block spyware before it can execute.

IE-SPYAD.EXE to block access to malicious websites so you cannot be redirected to them from an infected site or email. IE/Spyad places more than 4000 dubious websites and domains in the IE Restricted list. This severely impairs attempts to infect your system. It basically prevents any downloads (Cookies etc) from the sites listed, although you will still be able to connect to the sites. This is a self-extracting .ZIP file, save it to your desktop. Once downloaded, double-click on it to extract the files inside (default dir is C:\IE-SPYAD)

• Now navigate to C:\ie-spyad. Double click to open it.
• From within the folder, double-click install.bat
• Select Option #2 - Install the new IE-SPYAD list, by typing 2
• Then return to the main menu.
• Select option #4 - Add the old porn sites domain, by typing 4

Update all these programs regularly. Without regular updates you will not be protected when new malicious programs are released.

You may want to take a look at this well written article:

PC Safety and Security--What Do I Need?